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Eris E5 Hiss

egothrasher

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There is quite an audible hiss coming from the E5's, when nothing is playing and at idle. I currently have rca cables plugged in.

When I unplug them, the hiss does go down quite a bit. I have to be right up against them to hear the slight humm. With them plugged in though, I can the hiss quite clearly, even a few feet away.

I have the speakers on their own power strip, the only two things plugged into it. I have balanced cables coming in, to see if that helps at all. My cables coming from the DAC are currently split, one going to sub, other going to speakers. I don't know if that would cause any issues. I just ran the speakers directly from the DAC, same issues, so not the splitter.

All help/tips/suggestions appreciated.
 

AnalogSteph

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Could be a ground loop issue. I see you have a laptop, could you try that on battery just to see if it makes a difference?

If it doesn't, your input gain is too far up. (You'll have to match levels with the sub anyway.)

If it does, yep, ground loop - or rather, power supply noise via filter leakage.
I have balanced cables coming in, to see if that helps at all.
What kind? Does your DAC actually have balanced outputs? 99% of unbalanced to balanced adapter cables you can buy perform no better than plain unbalanced ones. Some you can at least modify.
 
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egothrasher

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Ok, so I tried unplugging the laptop. The hiss goes down quite considerably. I had thought having the speakers on a separate power strip would eliminate that. So, what can I do to combat that?
 

daftcombo

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Ok, so I tried unplugging the laptop. The hiss goes down quite considerably. I had thought having the speakers on a separate power strip would eliminate that. So, what can I do to combat that?
Try to put the speakers and sub on a power strip and the laptop, DAC... on another.

That trick worked for my JBL 305p mk2.

Also try reducing speakers gain.
 
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egothrasher

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I have tried those suggestions, and have reduced the input gain. Still a slight hum, not as bad as before. Does having a complete balanced setup eliminate the hum completely? Maybe my next upgrade down the road.
 

daftcombo

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I have tried those suggestions, and have reduced the input gain. Still a slight hum, not as bad as before. Does having a complete balanced setup eliminate the hum completely? Maybe my next upgrade down the road.
It didn't completely remove it for me.
 

trl

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I have tried those suggestions, and have reduced the input gain. Still a slight hum, not as bad as before. Does having a complete balanced setup eliminate the hum completely? Maybe my next upgrade down the road.
Probably the hiss comes from your source and there is nothing you can do. What DAC are you using?
 

AnalogSteph

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Ok, so I tried unplugging the laptop. The hiss goes down quite considerably. I had thought having the speakers on a separate power strip would eliminate that. So, what can I do to combat that?
Try to put the speakers and sub on a power strip and the laptop, DAC... on another.

That trick worked for my JBL 305p mk2.
Interesting. I had to think about this for a minute. I guess what happens there is that you make one half of the ground loop higher resistance like that.

The problem can also be tackled from the other side - use the audio cable with the lowest shield resistance you can find, or even run a piece of wire of substantial gauge alongside side the audio connection and bond the DAC audio ground and speaker chassis ground together like that (the wire could be terminated with crimp connectors that allow screwing it down, and most things with a metal chassis should have a suitable chassis screw somewhere... though SMSL seem to be using recessed screw heads).

Now this is all quite inelegant and brute-force. Actually making use of the balanced connection really is the much better option.
I am currently using the smsl mk2
Which one? Sanskrit 10th MkII (unbalanced only), M300 MkII (both), ...?

The hum, if also heard without any input connection, is likely to be mechanical in nature, coupled onto the chassis by the mains transformer. Cheap, small transformers tend to run close to saturation for maximum power output, and the mitigation of eddy currents within the core may be rather imperfect. This increases losses and mechanical vibration. This issue is quite well-documented on various Mackie models, my old Tascams had some as well, and in cheapie PC speakers it can be annoyingly loud. Even one of my K+H O110s will audibly hum sometimes, it seems it has a somewhat irritable toroidal that isn't overly fond of DC on the mains or something. This is one problem that devices with switch-mode supplies do not have for once.
 
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egothrasher

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Sanskrit 10th MK 2. Are there any suggestions for balanced DAC's. I was looking at either the one from drop, or the schitt audio
 
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egothrasher

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So I've found 3 things that makes the hum go away, and go back to normal sound. Normal as in what the monitors sound like when just powered on, with no inputs.

1. Unplug the usb from the dac/laptop so no input to the DAC.
2. Unplug the laptop power.
3. Unplug the rca cable input from the monitor, thus just powered on.
 

AnalogSteph

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Bamboszek

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RCA input of Presonus Eris series isn't the best. Had same problem with my Eris E8.
With Audient iD4 and balanced TRS cables these monitors are very quiet. Only faint noise when I put ear next to tweeter. 30cm further and noise is inaudible.
 

AnalogSteph

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RCA input of Presonus Eris series isn't the best.
To be fair, it's not specific to them. You will find similar issues with quite a number of active monitors when trying to use unbalanced input. Only a few seem to be suitable for that, e.g. M-Audio (like BX5 D2) or ADAM T*V series. I am still using a Behringer HD400 line isolator myself to interface my consumer soundcard with studio monitors.
 

bennybbbx

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I have tried those suggestions, and have reduced the input gain. Still a slight hum, not as bad as before. Does having a complete balanced setup eliminate the hum completely? Maybe my next upgrade down the road.

i hear it often RCA is bad and i notice myself on Kali. seem help only a USB soundbox or USB mixer and use symetrical connect to speakers. the 6,3 mm pawl connection need stereo cables(3 contacts). only then it is symetrical und no hum and no noise i hear. only of course the hiss of speaker itself
 
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